Moisture-proof receiver



J. J. COMER.

MOISTURE PROOF RECEIVER.

APPLICATION FILED 050.29. l9l7.

Inuemfur Jab .J Camera fiififia Patented Jan. 3, 1922.

WI g x 1 UNITED STATES PATENT OFFICE.

JOHN J. COMER, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO CHARLES R. BENNETT, O13 KANSAS CITY, MISSOURI.

MOISTURE-PROOF RECEIVER.

Specification of Letters Patent.

Patented Jan. 3, 1922.

To all whom it may concern Be it known that I, Join J. column, a citizen of the United States of America, and resident of Chicago, Cook County, Illinois, have invented certain new and useful Improvements in Moisture-Proof Receivers, of which the following is a specification.

My invention relates to receivers and to means for making electromagnetic receivers moisture proof. Among the objects of my invention are the following: To provide a receiver with a moisture proof diaphragm; to provide means for making a receiver moisture proof, and to provide other details of improvement tending to increase the efficiency and serviceability of a receiver. To accomplish the foregoing and other useful ends my invention consists in matters hereinafter set forth and claimed.

Referring to the accompanying drawings, Figure 1 shows a sectional elevation of the instrument through the middle along a plane at right angles to the limbs of the magnet.

Fig. 2 is a detail top view showing the knife edge of the vibrating armature.

The magnet shown in Fig. 1 has two steel limbs 2 and 3 which are bolted together near the lower end by a suitable bolt 6, clampmg between the two limbs a piece of soft iron 7 of suitable thickness to keep them a proper distance apart. This bolt 6 is also used as a clamp to hold a pair of terminals 41: and 5, one on each end of said bolt. Each terminal is insulated from the bolt and from the limbs of the magnet and each has a soldering terminal at one end and a screw terminal at the. other end. Near the upper end these two limbs are bolted together by a brass bolt 8, clamping between the .limbs a brass piece 9 and a soft iron pole piece 10. This bolt, furthermore, clamps to the outer side of the member 2 a brass support 11 and to the outside of the other member 3 a brass support 12. On the upper end of the pole piece 10 there is a magnetic coil 13 through the medium of which the armature 14: is operated. This armature has one end resting up against an angle heel piece 15 which is secured to the member 11 in any suitable manner as for example, by a screw. The other end of the armature which is elongated passes through a hole in the lower end of'the link 16 where the two are held together in a flexible joint by collodion. The other end of the link 16 is secured to the diaphragm 17 in any suitable manner. The diaphragm is mounted on the brass cup 18 between the insulating rings 19 of suitable soft material as for example, rubber, to keep it from metallic contact with the cup. This cup is secured to the brass supports 11 and 12 by suitable screws.

Just above the diaphragm 17 and resting on the upper insulating ring19 is a metal washer 22, and a pair of rubber gaskets 23. Between the rubber gaskets 23 is held a water proof or moisture proof diaphragm 24, preferably made of waterproof silk, which prevents any moisture from reaching the working parts, and still allows the sound produced by the diaphragm 17 to pass through the opening. The cup 18 is provided with a cap 20 which is secured to the cup by suitable screws which also serve to clamp in place the gaskets which hold the silk diaphragm. This cap has a threaded orifice into which the tube 21 is screwed as shown, the tube forming an exit for the sounds produced by the diaphragm 17. The whole instrument is mounted in and enclosed by a water proof box or casing 25 having a cover (not shown) which is removable and may be screwed to the box by means of the screw holes 27. Projecting from the two sides of the box and flush with the base thereof are four mounting brackets 28 for mounting said box against a wall or beam. In the lower end of said box is provided an opening in the form of a packing box, through which a cable 29 may be extended in order to carry out the wires from the binding posts 4 and 5. This packing box may be of any approved water proof type and comprises mainly a threaded plug 30 having an opening through which the cable may be passed, and a socket 31 hav ing a .similar opening. Both socket and plug have concave surfaces so that any suitable packing may be inserted and when the plug is forced into this socket, the packing is clamped tightly against the cable. In one side of this box is a plug 32 by means of which a key may be inserted for adjusting the screw 26. The instrument is mounted in this casing by means of the threaded tube 21 which is passed through an opening in the upper end of the box and held in place by the nut 33, a pair of rubber or other suitable washers 34 are provided, one on each side of the casing, which act to prevent any moisture from entering through the threads. It will be understood that a permanent magnet in this instrument acts upon, the armature 18 to draw it toward the pole piece 10 with considerable force. This armature in turn pulls on the diaphragm 17 and the end which rests on the limb 2 is only held there by magnetic force. There are no screws or other devices except the heel piece 15 to hold it in position. When the instrument is put together the connection between the armature 14 and diaphragm 17 is adjusted so that the diaphragm takes all the pull and holds the armature lifted from the pole piece 10 a suitable distance. Now, after the instrument is closed and connected up and put in use it sometimes becomes desirable to vary the adjustment of the armature 14. Ordinarily it is necessary to disconnect the instrument for doing this. Sometimes however, a series of links and levers are provided which enable the adjustment to be made without taking the instrument to pieces but it 1nvolves the mechanical meddling with the connection between the diaphragm and the armature which is detrimental to the instrument. Furthermore, in such cases the levers supplied to reduce the pull of the armature necessarily prevent the instrument from being sensitive enough to reproduce the higher harmonics that enable the ear to distinguish between the quality of one instrument and that of another or between the quality of voices. In the apparatus here disclosed the adjustment to which I refer is accomplished by the soft iron screw 26 without in any way disturbing mechanically the connection between the armature and the diaphragm. This screw operates to shunt off the lines of force from the armature 14a Even while the instrument is at work the adjustment may be carried on to vary it as described so as to adapt it for sounds of great'volume or sound of less volume. By moving the crew back and forth the armature 14 may be made to recede from or draw nearer to the bolt piece. IVith this instrument I have found it possible to reproduce properly the notes of a piano for example and also the human voice so that differences in quality are readily detected. Notwithstanding that the instrument is so accurate it is made with less parts and in a simpler manner than any similar instrument heretofore. The particular arrangement of the magnet and of the casing contribute not only toward making the instrument more compact and simple but contribute also to its efiiciency.

The magnet 13, which has as its core the pole piece 10, may be electrically connected,

through the medium of the terminals 4: and 5 and the cable 29 with any suitable circuit which may contain a microphone and a battery for energizing the electromagnet and for varying the energizing current in its circuit.

The particular arrangement which I have described therefore, shows a very efiicient method of mounting a loud speaking receiver in a thoroughly water proof casing so that although the moisture is prevented from coming into contact with the working parts, still the diaphragm is in such relation to the outer air that sounds made by it are not materially hindered and so that the adjustable part of said receiver are easily accessible and the instrument may be used in any place Without regard to atmospheric condition. Although I have shown my invention in connection with a reproducer of a certain specific type, it will be understood that I do not wish to be limited to its construction, but with my invention any type of reproducer may be sealed up in a similar manner.

What I claim is:

1. In combination an electromagnetic receiver, a case for keeping the receiver moisture proof, a water proof diaphragm for permitting sounds generated by the receiver passing out of the case, a cable for conveying a circuit conductor from a point outside of the case to said receiver, and a gland in the-case encircling said cable, said gland for pressing packing material around said cable for excluding moisture from the receiver.

2. In combination an electromagnetic receiver having a diaphragm and containing chamber, a cap for said chamber to which the receiver is secured, a moisture proof diaphragm held between the cap and the chamber, a conduit with an air passage leading from said moisture proof diaphragm to the external air, and means on said conduit for clamping the cap and conduit to the case for holding the receiver in position.

3. In combination an electromagnetic receiver, a case for keeping said receiver moisture proof, a water proof diaphragm for permitting the sounds generated by the receiver passing out of the case, said case provided with an opening for adjusting said receiver, and a threaded plug for closmg said opening.

4. In combination, a receiving device having means for receiving electrical waves and for converting them into sound waves, a moisture proof case for said receiver, a Water proof diaphragm for delivering sounds generated by the receiver to the outer air, a cable for conveying a circuit conductor from a point out side of the case to the receiver, and a gland in the case encircling the cable, said gland for pressing packing material around said cable for excluding moisture from the receiver.

5. In combination, a receiver having means for receiving electrical waves and for converting the same into sound waves, a case for keeping the receiver moisture proof, a water proof diaphragm for deliveringthe sounds generated by the receiver to the outer air, said case provided with an opening for adjusting the receiver, and a threaded plug for closing said opening.

6. In combination an electromagnetic receiver having a diaphragm and containing chamber, a moisture proof case for inclosing said receiver, a cap for said chamber to which the receiver is secured, a moisture proof diaphragm held between said cap and the chamber dividing the chamber into two sections, a conduit with an air passage leading from one of said sections to the external air, and means on said conduit for clamping the cap and conduit to the case for holding the receiver in position.

7. The combination of an electromagnetic receiver of the loud speaking type havin means for receiving electrical waves an for converting the same into sound waves,

entering by Way of the main diaphragm,

an opening in said casing adjacent said adjusting device, and means for closing said opening against moisture.

8. In combination with an electromagnetic receiver adapted for use in a telephone system to convert electrical waves into sound waves, or as a music reproducer and being arranged to carry a horn when used as a loud speaking receiver, a moisture proof case having a moisture proof diaphragm auxiliary to the main diaphragm for reventing moisture from entering the receiver through the horn, a packing case around the cable leading to said receiver, and an adjusting device for the receiver accessible through an opening which is also closed against moisture.

Signed by me at Chicago, Cook County, Illinois, this 29th day of Ma 1917.

J OHN J COMER. 

